Liquefied gas system



' 1940? L. J. WHITE LIQUEFIED GAS SYSTEM Filed May 26, 1939 Patented Dec. 17, 1940 I UNITED STATES PATENT OFFICE Southern Steel Company,

corporation of Texas San Antonio, Tex., a

Application May 26, 1939, Serial No. 276,024

Claims.

This invention relates to liquefied gas systems of the general type shown in Patents Nos. 2,121,673 and 2,121,675 and, among other objects, aims to provide greatly improved, relatively simple, eco- 5 nomical and dependable heat exchanging means associated with an underground tank and employing water as the source of heat to supplement the earths heat in vaporizing the liquefied gas and to supply revaporizing heat to any condensate that may be formed in the gas service pipe. The main idea is to provide a simple heat exchanger which can be assembled economically on a tank and which can be employed instead of the type of heat exchanger shown in Reissue Patent No. 20,624.

Other aims and advantages 'of the invention will appear in the specification, when considered in connection with the accompanying drawing, wherein:

Fig. 1 is a side elevation, partly in section, showing a system embodying the invention; and

Fig. 2 is a sectional view taken on the line 2-2 of Fig. 1.

Referring particularly to the drawing, the liquefied gas system there shown includes a tank l0 buried in the ground below the frost line and usually not less than two feet below the surface so that the gas known as butane stored in it under pressure absorbs vaporizing heat from the surrounding earth. In this instance, a combined filling and dispensing standpipe II is connected to the upper side of the tank and the filling and dispensing appurtenances, as shown in the aforesaid Patent 2,121,673 and Patent 2,121,675 are connected to the standpipe. However, this invention is applicable to othe types of underground systems. The appurtenances are housed within a protecting casing l2 so that they are accessible from above through a cover l3. The gas is delivered from the standpipe through the usual pressure reducing regulator I to a service pipe l5 emerging from one side of the casing and having its lowest portion parallel with the top portion of the tank. It is also buried in the ground below the frost line.

To supplement the earths heat and insure a constant supply of gas during cold weather, there is shown a liquid compartment in the form of a cylindrical extension [8 on the end of the tank below the service pipe. While this compartment may be formed in the tank by providin a partition near one end, it is preferably welded on the end wall of the tank. as shown. In this example, the compartment is filled with a liquid heating medium and is shown as being connected to a water supply pipe II, the tank being preferably buried in the ground adjacent to the pipe so that a section of it can be cut out to facilitate the water connections. However, any other suitable liquid heating medium may be employed. In this 5 example, the compartment has a long water inlet nipple l8 connected to the pipe l1 and a section of pipe l9 extending through the wall to a point near the bottom of the compartment connected to the other portion of the water main ll leading 10 to the housing. To enable the compartment to be filled initially with water, the pipe'section l9 has a small vent opening 20 in the upper portion of the compartment to permit displaced air to escape through the outlet side of the water main. 15 In this example, the service pipe I5 is shown as having a T fitting 21 above the compartment 16 and a spur tube or conduit 22 projects from the lower branch of the T into the compartment to a. point near the bottom, its lower end being closed l to provide a condensate trap in heat exchanging relation with the water in the compartment. The

T is located at the lowest portion of the service pipe so that any condensate formed in the service pipe may drain to it and thence into the trap, 5" where it will be vaporized by the heat of the water in the heat exchanging compartment. The water connections to the compartment are so arranged as to insure circulation of fresh water through the compartmentand a maximum heat transfer from the water to the tank and/or the condensate trap. If both connections were made at the top portion of the compartment, the relatively warm water would pass into the top portion and out of the top portion without circulating through the entire compartment because the cold water would remain in the bottom portion. The present arrangement insures that the relatively warm water will enter at the top and the cold water will be delivered to the house main from the bottom of the compartment. Furthermore, this has the added advantage of cooling the water in the house main before it reaches the house and prevents the water in the compartment from freezing during cold weather. The shape of the compartment is 5 such that if ice is formed in it, its walls can bulge so that it will not be ruptured.

From the foregoing description, it will be seen that the heat exchanger is simple in its construction and very easy to apply to a tank. The pipe 50 fittings may be assembled on itat the factory so that it is only necessary for an ordinary plumber to make the necessary connections between the pipes and the water pipe and gas service pipe when the system is installed.

present invention is not reparticular embodiment thereoi.

.connecting the water chamber to a source or water supply so that the Water circulates therein; and a gas service pipe having its lowest portion adjacent to said heat exchanger and connected to absorb vaporizing heat therefrom.

2. In a liquefied gas system of the character described having an elongated pressure storage tank adapted to be buried in the ground, a cup shaped sheet metal member welded on one end of the tank to provide a heat exchanging water compartment; water circulating pipes connecting said compartment to a source of water supply and having means to permit said compartment to be initially filled withwater; a gas service pipe above said compartment; a T in the lowest portion of said gas service pipe; and a vertical spur tube projecting from the T into the lower portion of the water compartment and having its lower end closed, serving as a trap for any condensate formed in the service line and to absorb revaporizing heat from the water in said compartment.

3. In a liquefied gas system of the class described having a cylindrical pressure storage tank, a heat exchanger comprising a closed metal chamber in heat exchanging contact with one end wall of the tank and filled with a liquid heating medium; a' gas service pipe having its lowest portion adjacent to said heat exchanger; and a spur pipe closed at its lower end connected to the service pipe at its lowest point and projecting downwardly into said chamber to absorb revaporizlng heat from the liquid therein.

4. In a liquefied gas dispensing system or the character described having a cylindrical pres sure storage tank adapted to be buried in the ground, a heat exchanger including a closed chamber at one end of the tank forming an extension thereof and containing a liquid heating medium; a gas service pipe connected to the tank having its lowest point above the chamber; and a condensate trap connected to the low point of the service pipe and arranged in heat exchanging relation with the chamber to revaporize condensate in the trap.

5. As an article of ma ufacture, a cylindrical pressure storage tank for liquefied gas systems having a closed heat exchanging chamber secured to one end wall of the tank on the outside with the end wall of the tank forming a. Wall of the chamber, said chamber forming an extension of the tank and adapted to be filled with a liquid heating medium to supply vaporizing heat to the contents of the tank; and means connected to supply liquid to the chamber.

LOYD J. WHITE. 

